ENZYMOLOGY

Question 1

What is the highest degree of creatine kinase elevation associated with?

Answer 1

Pronounced elevation: Duchenne’s muscular dystrophy, polymyositis, dermatomyositis, myocardial infarction.

Question 2

What are the tissue sources of creatine kinase?

Answer 2

Brain, myocardium (heart), skeletal muscle.

Question 3

What is the diagnostic significance of mild to moderate elevation of creatine kinase?

Answer 3

Acute agitated psychosis, alcoholic myopathy, severe exercise, delirium tremens, severe ischemic injury, pulmonary infarction, intramuscular injections, hypothyroidism, muscular trauma.

Question 4

What are the isoenzymes of creatine kinase?

Answer 4

CK-BB (CK1), CK-MB (CK2), CK-MM (CK3).

Question 5

What is the significance of CK-BB (CK1)?

Answer 5

Elevated in CNS damage, tumors, presence of macro-CK; negligible in serum.

Question 6

What is the significance of CK-MB (CK2)?

Answer 6

Present in significant amounts in cardiac tissue; <6% of total CK in serum.

Question 7

What is the major isoenzyme found in striated muscle?

Answer 7

CK-MM (CK3) is the major isoenzyme found in striated muscle and normal serum (94-100%).

Question 8

What are the methods for CK determination?

Answer 8

Tanzer-Gilvarg (forward reaction), Oliver-Rosalki (reverse reaction).

Question 9

What are the reference values for total CK?

Answer 9

Male: 15-160 U/L; Female: 15-130 U/L.

Question 10

What is lactate dehydrogenase (LDH) known for?

Answer 10

Least tissue-specific; cannot stand alone, must be combined with other tests.

Question 11

What are the major tissue sources of lactate dehydrogenase?

Answer 11

Heart, RBCs, renal cortex, lungs, lymphocytes, spleen, pancreas, liver, skeletal muscles.

Question 12

What is the diagnostic significance of pronounced elevation of LDH?

Answer 12

Megaloblastic/pernicious anemia, renal infarction, systemic shock and hypoxia, hepatic metastases, hepatitis.

Question 13

What are the methods for LD determination?

Answer 13

Wacker (forward reaction), Wroblewski-Ladue (reverse reaction).

Question 14

What is the reference range for LDH?

Answer 14

100-225 U/L (37°C).

Question 15

What are the tissue sources of aminotransferases/transaminases?

Answer 15

Liver, heart, skeletal muscle.

Question 16

What is the diagnostic significance of pronounced elevation of AST/SGOT?

Answer 16

Acute hepatocellular disorders, circulatory collapse, myocardial infarction.

Question 17

What is the De Ritis ratio?

Answer 17

AST/ALT ratio; significant in assessing liver conditions.

Question 18

Isoenzymes for heart, rbcs and renal cortex

Answer 18

LDL1 and 2

Question 19

Isoenzymes for lungs, lymphocytes, spleen, pancreas

Answer 19

LD3

Question 20

Isoenzymes of liver and skeletal muscles

Answer 20

LD4 and 5

Question 21

Increased in AHCDS

Answer 21

Cytoplasmic AST

Question 22

Increase in Fulminant Hepatic Failure

Answer 22

Mitochondrial AST

Question 23

Increase in Alcoholic liver disease

Answer 23

Mitochondrial AST

Question 24

Alcoholic liver disease De Ritis Ratio:

Answer 24

> 2 (3-4)

Question 25

Longest half-life

Answer 25

Mitochondrial AST

Question 26

Longer half-life than AST

Answer 26

ALT/SGPT

Question 27

Increased absorbance 340 nm LD determination

Answer 27

Wacker

Question 28

Decreased absorbance 340 nm LD determination

Answer 28

Wroblewski-Ladue

Question 30

What is the Reitman-Frankel method used for?

Answer 30

It is used for AST/ALT determination using 2,4-dinitrophenylhydrazine and 0.4 N NaOH.

Question 31

What does the Coupled Enzymatic Reaction method rely on?

Answer 31

It is based on the Karmen method for AST/ALT determination.

Question 32

What are the reference values for AST?

Answer 32

3-35 U/L.

Question 33

What are the reference values for ALT?

Answer 33

7-45 U/L.

Question 34

What is the first marker in the summary of MI markers?

Answer 34

Myoglobin.

Question 35

What is the diagnostic significance of alkaline phosphatase (ALP) elevation?

Answer 35

Pronounced elevation indicates bile duct obstruction, biliary cirrhosis, Paget's disease, osteogenic sarcoma, and hyperparathyroidism.

Question 36

What are the tissue sources for alkaline phosphatase?

Answer 36

Liver, bone, placenta, and intestine.

Question 37

What is the reference method for ALP determination?

Answer 37

Bowers - Malamb method.

Question 38

What are the reference values for ALP?

Answer 38

30-90 U/L.

Question 39

What is the significance of lipase in diagnostics?

Answer 39

It is significant in diagnosing acute pancreatitis.

Question 40

What are the methods for amylase determination?

Answer 40

Amyloclastic, saccharogenic, chromogenic, and coupled-enzymatic methods.

Question 41

What are the reference values for serum amylase?

Answer 41

25-130 U/L.

Question 42

What is the reference value for urine amylase?

Answer 42

1-15 U/h.